Last FREAKING Week 15 - Potpourri Flashcards
1
Q
What is Postoperative Nausea and Vomiting (PONV)?
A
Nausea, retching, or vomiting in the postanesthesia care unit (PACU) and in the immediate 24 hour postoperative hours.
2
Q
What is Post discharge nausea and vomiting (PDNV)?
A
Symptoms that occur after discharge for outpatient procedures.
(She said it is after the 24 hours).
3
Q
is a major causes of dissatisfaction after anesthesia and frequent cause of unexpected hospital admission after ambulatory surgery.
A
Prolonged vomiting
4
Q
T/F: Patients often rate PONV as worse than postoperative pain
A
True
5
Q
T/F: Patients often rate PONV as worse than postoperative pain
A
True
6
Q
POV affects ______ % of all surgical patients,
incidence of nausea is ______%
and
PONV in high risk patients can be up to _______%
A
30;
50
80
7
Q
Risk of PONV in Adults
A
Female
Opioid analgesia
GA*
Hx of PONV or motion sickness.
Age: younger
Non-smokers
Duration of sx
Surgery type.
8
Q
PONV is associated (2) with :
A
- delayed discharge from the PACU
- increased admission
9
Q
Risk for PONV in adults using the Apfel Simplified Risk Score:
How does it work?
A
0, 1, 2, 3, and 4 risk factors correspond to PONV risks of approximately 10%, 20%, 40%, 60%, and 80%, respectively
10
Q
Risk Factor Scores for PDNV
A
Female Gender
History of PONV
Age <50
Use of opioids in PACU
Nausea in PACU
11
Q
Postdischarge Nausea and Vomiting (PDNV) is associated with (2):
A
- delayed return to work/normal activities.
- Emergency Room (ER) visits and hospital readmission
12
Q
Risk score for PDNV in adults using the Apfel Simplified Risk Score:
How does it work?
A
0, 1, 2, 3, 4, and 5 risk factors correspond to PDNV risks of approximately 10%, 20%, 30%, 50%, 60%, and 80%, respectively
13
Q
Potential Consequences of PONV (7):
A
- Increased cost
- Increased admission rates (ambulatory care)
- Suture dehiscence
- Aspiration
- Increased ICP
- Pneumothorax
- Patient Dissatisfaction
14
Q
Factors that increase PONV: (9)
A
- Duration of anesthesia
- Anesthetic technique
- Volatile anesthetics
- Nitrous, neostigmine?, Opioids, Methohexital, Etomidate
- Hypotension, Dehydration, Fasting
- Experience of the anesthetist
- Placement of airways
- Hypercarbia, Gastric insufflation
- Sympathetic stimulation
15
Q
Types of surgery that can cause PONV in adults:
A
Cholecystectomy
Gynecologic (GYN)
Laparoscopic Procedures
Eye and Ear surgery
Shoulder?
16
Q
Types of surgery that can cause PONV in children:
A
- Inguinal, scrotal or penile procedures
- Strabismus surgery
- A denotonsillectomy
ISA is my cousin’s daughter! she is always vomiting!!
(Dr. R said these also fit for adults)
17
Q
The pathophysiology of PONV involves central and peripheral mechanism.
5 principle neurotransmitter receptors are involved:
A
- Anticholinergic/Muscarinic M1
- Dopamine D2
- Histamine H1
- 5-hydroxytryptamine (HT) 3 serotonin
- Neurokinin 1 (NK1) or
- Substance P
All of these receptors may be targets for prevention or treatment of PONV
18
Q
The chemoreceptor Zone (CTZ) is located where?
and what two-neurotransmitters does it involve?
A
- in 4th ventricle in the area postrema.
- Dopamine D2 and 5HT-3
19
Q
What drugs and toxins is the the CTZ susceptible to? and why?
A
(Chemo), anesthetic agents, opioids.
- Not protected by the blood brain barrier
20
Q
What is the vestibular system responsible for?
and what are the neurotransmitter involved?
A
- Motion and equilibrium, middle ear
- Histamine H1 and Muscarinic M1
21
Q
Where is the vomiting center?
A
in nucleus tractus solitarius in postrema and lower pons.
22
Q
What in the GI tract can cause PONV?
A
- Afferent vagus nerve (stimulation).
- Enterochromaffin cells release serotonin
23
Q
Areas in the body involved with PONV:
A
- CTZ
- Vestibular system
- Vomiting center
- Cerebral cortex
- GI tract
24
Q
Strategies to Reduce Baseline Risk of PONV:
A
- Avoidance of GA by the use of regional anesthesia.
- Use of propofol for induction and maintenance of anesthesia.
- Avoidance of nitrous oxide in surgeries lasting over 1 hr.
- Avoidance of volatile anesthetics.
- Minimization of intraoperative and postoperative opioids.
- Adequate hydration.
- Using sugammadex instead of neostigmine for the reversal of neuromuscular blockade.
25
Prevention of PONV includes:
- Monotherapy or Combination (additive)
- Anesthesia technique (Regional, TIVA)
- Opioid sparing/Postop pain control
- Supplemental O2 concentration
- Avoid hypotension
26
Opioid sparing/Postop pain control medications:
Celebrex and
Neurontin,
Tylenol (IV or PO)
NSAIDS
Ketamine
Precedex
Robaxin
27
Treatment/ Pretreatment of PONV durgs:
and others not used as much?
- Scopolamine patch
- Reglan
- Decadron
- Zofran
- Propofol
- Vistaril/ Ephedrine
Others:
- Fluids?
- Phernergan (Phenothiazine)
- Butyrophenones (droperidol and haldol).
28
Scopolamine MOA and application.
- Competitive inhibitor at muscarinic sites.
- 2 hours prior to induction of anesthesia and remove 24 hours after use
29
Reglan - MOA?
dopamine 2 antagonist
30
Decadron class and dose.
Decadron 4-8 mg on induction (steroid)
31
Zofran - MOA and dose?
- 5-HT3 receptor antagonist.
- 4 mg at the end of surgery.
32
Vistaril dx class and dose?
- Histamine 1 antagonist.
- Vistaril/Ephedrine 25/25 mg IM
33
Neurokinin 1/Substance P antagonists are used to treat what?
which meds are included in this group?
Chemo-induced N/V (CINV).
- Aprepitant PO (half like of 40 hours)
- Fosaprepitant IV
- Rolapitant PO/IV(half life of 180 hours)
34
Incidence of PONV is greater than ______% following balanced anesthesia
50
35
Opioids cause PONV by their effects on what?
The chemoreceptor zone (CTZ) in the area of the postrema of the brainstem
36
Movement (moving the patient, transport to the PACU) can cause N/V due to:
increased sensitivity of the vestibular system
37
The CTZ contains what receptors?
- Opioid
- seretonin (5HT3)
- histamine
- dopamine (D2)
- muscarinic acetylcholine receptors.
38
which three organs send neural projections to the vomiting center in the medulla?
- CTZ
- Vagal nerve
- Vestibular
39
Some of the Opioid-free anesthesia meds include:
Exparel
Magnesium,
Lidocaine IV
Ketamine infusion
Propofol infusion
Antiemetics
NSAID,
Tylenol,
Gabapentin,
Celebrex
40
Enhanced Recovery After Surgery (ERAS) meds includes:
TIVA
Ketamine, Precedex, Lidocaine, Magnesium
**Regional Anesthesia/Transabdominal Blocks (TAP block)**
Gabapentin, Celebrex, Robaxin
IV or PO Tylenol
NSAIDs
Exparel (liposomal bupivacaine)
**they can have opioids**
41
Clinical considerations for an ERAS patients:
- No NG tubes
- Carbohydrate rich clear drink allowed up to 2 hours before surgery.
42
How the body regulates temperature
Thermoregulation
43
Thermoregulation is a 3 - phase process:
- Afferent thermal sensing
- Central regulation or control
- Efferent responses
44
Autonomic responses to heat:
- Sweating and active cutaneous vasodilation.
45
Sweating is mediated by:
postganglionic cholinergic nerves.
46
Autonomic response to cold:
- Cutaneous vasoconstriction mediated by alpha-1 adrenergic receptors
- *Synergistically augmented by hypothermia-induced alpha-1 and 2 receptors*
47
4 mechanisms of Heat Loss
Radiation
Conduction
Evaporation
Convection
48
#1 source for heat loss
Radiation
49
what is Radiation?
acoount for how much heat loss?
and depends on what?
- Dissipation of heat to cooler surroundings
- Accounts for greatest patient heat loss (between 40-60%)
- Depends on cutaneous blood flow and exposed body surface area
- Head (keep head cover).
50
#2 source for heat loss
Convection
51
What is Convection?
accounts for how much heat loss?
- Airflow over exposed surfaces
- Accounts for about 15-30% of intraoperative heat loss
52
What is evaporation?
accounts for how much heat loss?
Heat loss through the conversion of water to gas (body perspires)
Accounts for about 8-10% of heat loss during surgery
Major open wound surgery can have significant loss
53
What is conduction?
accounts for how much heat loss?
Heat loss through physical contact with another object
Accounts for about 5% heat loss
Contact with a cold surface (bed, mattress)
54
What is the definition of hypothermia?
A. When you look like the guy over there………
B. Core temperature below 36
C. Core temperature below 35
D. When you’re so cold that when you inhale your snot freezes
B. Core temperature below 36
55
Which of the following is **not** an adverse effect of intraoperative hypothermia?
A. Increased risk of infection
B. Increased risk of DVT/PE
C. Increased duration of neuromuscular blockade
D. Increase cardiac morbidity
E. Increased blood glucose
F. Delayed drug metabolism
G. Vasoconstriction
H. Hypertension and tachycardia
They are all adverse events!!!
56
Risks of Hypothermia in the Surgical Patient:
- Wound infection and delayed healing.
- Increased O2 consumption through shivering.
- Increased risk of cardiovascular incidents (triples incidence of VT and cardiac events).
- Increased rate of sickling in sickle cell patients.
- Reduced platelet function and impairs activation of the coagulation cascade
57
Patients at high risk for hypothermia:
Elderly
Neonates
Intoxicated folks
Certain drugs
Female
58
Why are elderly at risk of hypothermia?
decreased subcutaneous fat and alteration in their hypothalamic function.
59
Why are neonates at risk of hypothermia?
immature thermoregulatory center and high surface area to body mass ratio, response to shivering is absent (nonshivering thermogenesis).
60
Why are intoxicated folks at risk of hypothermia?
vasodilation and depression of their heat regulatory center.
61
Which drugs cause hypothermia?
- vasodilators
- NSAIDs
- Phenothiazine
62
If temperature falls from 37 to 35 by how much does the risk of infection increase?
and why?
- 2 - 3 times
because of **vasoconstriction** leading to:
- Decreased blood and O2 delivery to the wound.
- Decreased superoxide production
63
If Intraop temp falls to 35 degrees it will increase the hospital stay by:
2.5 days
64
If Intraop temp falls to 35 degrees it will increase the hospital stay by:
2.5 days
65
How can GA lead to hypothermia?
- by Peripheral vasodilation,
- altered thermoregulation,
- and inability to generate heat by shivering
66
How can a neuraxial blockade lead to hypothermia?
- Result of sympathetic blockade,
- muscle relaxation,
- and a lack of afferent sensory input into central thermoregulatory centers
67
Cold fluids, blood, prep solutions, and exposure can lead to?
Hypothermia
**Never give anything cold**
68
The fall in temperature during general anesthesia follows a characteristic pattern and has three phases:
- An initial rapid decrease of approximately 0.5 to 1.5°C over approximately 30 minutes
- A slow linear reduction of about 0.3°C per hour
- A plateau phase
69
describe what happens to the core body temperature after the administration of ANE
pt vasodilates and core body temp decreases while peripheral temp increases
70
If the temperature falls from 37 to 35.5, what is the average increase in estimated blood loss (EBL)?
500 cc
*decreased activity of clotting factors*
71
why is ti difficult to see hypothermia of bloodwork/labs
- conflicting date on the temp which labe are run so **dont** see hypothermia induced coagulopathy on coag panel
- TEG usually warmed too but doesnt have to be
72
Compared to temperature of 35 degrees, normothermia is associated with a reduction in ________ by 55%
cardiac morbidity
73
why is hypothermia bad for the heart?
**SHAT**
- shivering
- hypertension
- arrythmias
- tachycardia
74
what happens to EKG in hypothermic pt for each:
mild
moderate
severe
mild - sinus bradycardia
moderate- **prolonged** PR & QT anddddd **widened** QRS
severe - elevation at the junction of QRS and ST known as **hypothermic hump/ J wave (Osborne)**
75
MAC is decreased ______ per degree C decrease in core body temperature
5-7%
76
how do opioids potentiate hypothermia
depress voluntary shivering that would generate heat
77
what happens to each in hypothermia:
Liver
Renal
Protein binding
muscle relaxants
L- decreased hepatic BF decreases metabolism
R - decreased renal BF and clearance
PB- **increases**
MR- prolonged
78
During the first hour after induction of anesthesia, core body temperature can drop by 1-1.5 C due to what?
A. The OR is so, so cold you can blow frost rings with your mouth
B. Radiation heat loss from the patient to the air
C. Redistribution of body heat from core to periphery
D. Evaporative heat loss
C
79
heat loss order (and %) in children
1. radiation (39%)
2. Convection (39%)
3. Evaporation (24%)
4. Conduction (3%)
80
The temperature in the room should be increased to about _____ before nonfebrile neonates and infants arrive
28 degrees C
81
the most common heat loss type in adults in surgery
second most common
1st- radiation
2nd - convection
82
How can we prevent or decrease the drop in patient temperature from redistribution after induction?
Increasing mean body temperature by **Pre-warming**
*usually requires about 30 minutes to be effective*
83
What is the most effective non-invasive method of warming a patient?
Forced air-warming blanket
*Bair Hugger*
84
What is the overall most effective method for warming
a patient (invasive and noninvasive)?
Cardiopulmonary bypass
85
Where is the most accurate place to measure body temperature (closest to what the hypothalamus sees)?
A. Rectal
B. Bladder
C. Nasopharyngeal
D. Distal Esophagus
E. Axillary
D
86
gold standard for temperature monitoring
pulmonary artery (PA)
87
define hyperthermia
rise in body temp of 2 degrees C/hr **OR** core temp> 38 C
88
Describe the incidence of hyperthermia in the OR and its causes
uncommon
usually d/t sepsis or overheating due to active warming. MH or other syndromes
89
conditions associated with hyperthermia (6)
1. MH
2. NMS
3. pheochromocytoma
4. sepsis
5. transfusion reaction
6. serotonin syndrome
90
symptoms of MH
1. tachycardia/arrhythmias (earliest sign is tachycardia but **not specific**)
2. tachypnea
3. hypercarbia
4. muscle rigidity
5. rhabdomyolysis
6. acidosis
7. hyperkalemia
8. skin mottling
9. profuse sweating
10. altered BP
91
T or f: Those susceptible to MH have a mutation of the ryanodine receptor that allows controlled release of calcium from SR
F -- **Uncontrolled**
92
__% or greater of MH cases are linked to the RYR1 located on chromosome ___
70
19
93
In MH, the channel is the RYR1 because it binds to ______
plant alkaloid ryanodine
94
MH is inherited as
autosomal dominant
**does NOT skip generations**
95
Associated skeletal muscle diseases of MH
* Central core disease
* King-Denborough syndrome
* Multiminicore disease
* Centronuclear myopathy
* Congenital fiber-type disproportion * Native American myopathy
96
MH triggered by
IAs and SCh
97
the most sensitive and specific sign of MH
Increase in **end-tidal carbon dioxide** during constant ventilation
98
in MH, Generalized rigidity has extremely high________
specificity
**NOT** sensitivity
less sensitive/specific than EtCO2 increase
99
typically in MH, temperature incerases (not commonly higher than ____ degrees Celsius)
40
100
what is Hyperkalemic Cardiac Arrest
Sudden hyperkalemic cardiac arrest after MH triggering agents in children with undiagnosed myopathy, especially dystrophinopathies, Duchenne or Beckers muscular dystrophy
**Not** a result of pathophysiologic changes typical of MH, its related to a **muscle membrane destruction leading to
hyperkalemia**
101
electrolyte findings for K, Ca, and Mg in MH
all increase
*only thing that decreases is pH and PO2*
102
how to prep ANE machine for known/suspected MH risk
1. disable/remove vaporaizers
2. new breathing circuit/ reservoir bag to y piece and set vent to inflate (10 L/min of FGF for up to 60-90 min/old machines and for 20 min for new machines)
3. changes CO2 absorbant
4. attach activated charcoal filters to both limbs of breathing circuit and during prooceudre to reduce vapor concentration to < 5 ppm
103
how to prep OR/supplies for known/suspected MH risk
1. Prep ANE machine
2. locate MH cart
3. cover/tape SCh or remove it from med cart
104
alternatives for known/suspected MH risk
1. regional
2. TIVA
3. local
4. N2O
5. benzos
6. Narcotics
105
T or F: in the event of an MH crisis, the CRNA should stop anesthetic triggering agents, change the machine/circuit, and increase FiO2
F -- do **NOT** change machine or circuit
*ppt slide 68
106
treatments for Hyperkaelmie
- calcium chloride 10 mg/kg IV (max 2000 mg)
- calcium gluconate 30 mg/kg IV (max 3000 mg)
- D50 1 amp IV + regular insulin 10 units IV
- sodium bicarbonate 1-2 mEq/kg(max 50 mEq)
107
if MH occurs, whta should the UO goal be
1-2 mL/kg per hour
*may give diuretics and fludis*
108
in MH crisis, what should you do if CK or urine myoglobin elevated
consider alkalinizing the urine
109
What is the dose for Dantrolene and Ryandodex and how are they prepared
Dose = 2.5 mg/kg
Dantrolene - 20 mg vial *diluted* with 60 mL preservative-free sterile water
Ryanodex - 250 mg vial *diluted* with 5 mL preservative-free sterile water
110
if metabolic acidosis is suspected in MH crsis, administer
sodium bicarbonate 1-2 mEq/kg
111
How does Dantrolene/Ryanodex work?
* Direct-acting skeletal muscle relaxant, **hydantoin derivative**
* Directly interferes with muscle contraction by inhibiting Ca2+ release from the SR
* Possibly binds to the RYR1 receptor
* Can also lower the temp in NMS and thyroid storms
112
The most accurate diagnostic for MH is exposure of biopsied skeletal muscle to ____, _____, and ________.
how is this test performed
- halothane, caffeine, and ryanodine
* Biopsy from the thigh and suspended in a water bath at 37 degrees Celcius
* Then exposed to halothane, caffeine or ryanodine
* Isometric contracture is measured with a strain gauge
* Threshold and height of contracture is measured, and a diagnosis of MH is based off those measurements
113
biopsy skeletal muscle to test for MH is highly______ and close to____%. ____% of positive results are false-positives
sensitive
100
20
114
S/S of NMS
- Muscle Rigidity/rhabdomyolysis
- acidosis
- tachycardia
- Increased temperature
* Depressed consciousness
* Autonomic instability
115
medications that cause NMS
- Compazine
- Reglan
- Droperidol
- Phenergan
- neuroleptics
- antidopinergics
- phenothiazines
*central dopaminergic blockade at the hypothalamus*
116
treatment for NMS
- benzos
- dopamine agonist (bromocriptine)
- maybe dantrolene
117
S/S of Serotonin Syndrome
- Mental status changes
- Autonomic hyperactivity (fever, tachycardia, hypertension, diaphoresis) - Neuromuscular abnormalities (tremor, **hyperreflexia**)
118
causes for Serotonin Syndrome
- SSRIs
- MAOI
- TCAs
- amphetamines
- Demerol
- methylene Blue
119
treatment for Serotonin Syndrome
- Active cooling
- IV fluids
- increase the anesthetic depth to decrease autonomic hyperactivity
- serotonins antagonist (Chloropromazine IV or Cyproheptadine PO)
120
Drugs that can Increase risk for Hyperthermia
**drugs that increase BMR and heat production**
- Sympathomimetic drugs
* Monoamine oxidase inhibitors
* Cocaine
* Amphetamines
* Tricyclic antidepressants
**increases temps by supressing sweating**
- anticholinergics
- antihistamines
121
How to treat Hyperthermia
* Expose skin surfaces * Cooling blankets
* Ice packs
* Cool fluids
* Antipyretics
* Treat the cause
* TURN OFF THE BAIR HUGGER
